I came across a problem - it seems that my multithreaded ROOT app uses only single core. I tried also thread samples and they too seem to use a single core. Thread::Ps() returns two threads running at the same time, so I guess it should be scheduled to multiple cores…
Is there anything special I should specify during compilation or some other trick to make TThreads tun on multiple cores?
I have to add that normal pthreads work fine on my machines - two threads are split over to two cores, top showing ~195% of CPU usage for the process. No such think with ROOT TThreads. Really, noone can help?
OK, finally I found the problem. Frequently used TThread::Lock() caused only 1 core to be used.
It seems for me, that the same problem is visible in the only tthread sample from tutorial, that utilizes lot’s of cpu - threadsh1.C. Not sure about that, but perhaps this sample should/could be rewritten to make use of multiple cores.
Hi,
Simply reducing the frequency of the updates (by increase the value of upd) will get you the desired effect in threadsh1.C
Cheers,
Philippe.